A-plane (1 (2) over bar1 0) AlN films were deposited on the off-angle R-plane (1 (1) over bar 0 2) sapphire substrates, in which the surface plane was tilted towards the [1 (1) over bar 01] sapphire direction, by metalorganic chemical vapor deposition in order to clarify off-angle effects. The polar direction of the AIN him was inverted by changing the sign of the off-angle and the off-angle was effective in restraining the generation of inverted twins in the AlN. A minus off-angle was found to improve total crystal quality of the AlN from X-ray diffraction results. High-resolution transmission electron microscopy images in the vicinity of interfaces between the AIN and the sapphire indicated that atomic arrangement at an initial AIN growth stage influenced the total crystal quality.